Influence of emulsion droplet size on antimicrobial properties
In this study the effect of oil droplet size on antimicrobial activity was investigated. Oil-in-water emulsions were made from oil possessing antimicrobial properties (lemon myrtle oil, LMO), and oil which has no antimicrobial properties (soybean oil). The antimicrobial properties were investigated against 5 bacteria. The emulsions containing millimetre size and micron-size droplets were produced by hand-shaking and blending using a high speed blender and nanoemulsions were produced using a microfluidizer at 60 MPa. It was found that all emulsions made from LMO had the same level of antimicrobial effects against the 5 bacteria whereas all soybean oil emulsions had no antimicrobial effect. From these results, it could be concluded that the antimicrobial property of nanoemulsions result from the active ingredients in the emulsions and not from high surface tensions and cell wall diffusion activity of nano-sized droplets.
Keywordsnanoemulsion antimicrobial property lemon myrtle oil microfluidization droplet size
Unable to display preview. Download preview PDF.
- 1.Yaghmur A, De Campo L, Sagalowicz L, Leser M, Glatter O, Michel M, Watzke H, Watzke HJ. Oil-in-water emulsion for delivery of active compounds, e.g., flavor and vitamins, comprises oil droplets exhibiting nano-sized structure containing hydrophilic domains and formed by lipophilic additive. Patent No. EP1598060-A1 (2005)Google Scholar
- 2.Choi AJ, Kim CJ, Cho YJ, Hwang JK, Kim CT. Effects of surfactants on the formation and stability of capsaicin-loaded nanoemulsions. Food Sci. Biotechnol. 18: 1161–1172 (2009)Google Scholar
- 4.Magdassi S, Dayan B, Levi-ruso G. Pesticide nanoparticles Obtained from microemulsions and nanoemulsions. Patent No. WO/ 2008/032328 (2008)Google Scholar
- 8.Baker JR, Shih A, Myc A, Hamouda T. Composition for anti-fungal treatment comprises an antimicrobial oil-in-water nanoemulsion containing a solvent and a surfactant. Patent No. WO2003000243-A, WO2003000243-A1 (2003)Google Scholar
- 14.Choi SI, Chang KM, Lee YS, Kim GH. Antibacterial activity of essential oils from Zanthoxylum piperitum A.P. DC. And Zanthoxylum schinifolium. Food Sci. Biotechnol. 17: 195–198 (2008)Google Scholar
- 17.Huynh VT. Encapsulation of lemon myrtle oil and its biological functionalities. MPhil Thesis, The University of Queensland, Brisbane, Australia (2007)Google Scholar